Fluid control apparatus

ABSTRACT

A method and apparatus for controlling fluid flow from a variable pressure source by a housing which is provided with an inlet for receiving flow from a variable pressure source and an outlet for discharging flow from the housing. Flow constrictor means are mounted within the housing in the form of spaced orifice plates defining flow chambers therebetween. A double acting ram is provided with a conical member mounted thereon with its apex pointed upstream to position the conical member within the orifice plates and chambers defined therebetween to stepwise reduce the pressure and velocity of the variable pressure source. Means measure the pressure of the variable pressure source at the housing inlet and operate valve means and motor means so that the ram with the conical member thereon may be positioned longitudinally relative to the orifice plates and chambers in response to the pressure of the source measured at the housing inlet to thereby restrict flow from the variable source through the housing. The ram is sealably and movably mounted within the housing so that the fluid medium which controls its position, while acting in response to the variable pressure from the source at the housing inlet does not comingle with the fluid pressure from the source during its passage from the inlet to the discharge end of the housing.

United States Patent 1191 Hayatdavoudi FLUID CONTROL APPARATUS AsadollahHayatdavoudi, Madison, Wis.

[75] Inventor:

[73] Assignee: Petroleum Associates of Lafayette,

lnc., Lafayette, La.

22 Filed: Mar. 12, 1973 [21] Appl. No.: 340,577

[52] US. Cl 251/122, 166/53, 175/25 [51] Int. Cl. F16k 47/00 [58] Fieldof Search..... 166/53; 137/488, 1; 175/25,

Primary Examiner-Henry T. Klinksiek [57] ABSTRACT A method and apparatusfor controlling fluid flow from a variable pressure source by a housingwhich is Feb. 12, 1974 provided with an inlet for receiving flow from avariable pressure source and an outlet for discharging flow from thehousing. Flow constrictor means are mounted within the housing in theform of spaced orifice plates defining flow chambers therebetween. Adouble acting ram is provided with a conical member mounted thereon withits apex pointed upstream to position the conical member within theorifice plates and chambers defined therebetween to stepwise reduce thepressure and velocity of the variable pressure source.

Means measure the pressure of the variable pressure source at thehousing inlet and operate valve means and motor means so that the ramwith the conical member thereon may be positioned longitudinallyrelative to the orifice plates and chambers in response to the pressureof the source measured at the housing inlet to thereby restrict flowfrom the variable source through the housing. The ram is sealably andmovably mounted within the housing so that the fluid medium whichcontrols its position, while acting in response to the variable pressurefrom the source at the housing inlet does not comingle with the fluidpressure from the source during its passage from the inlet to thedischarge end of the housing.

3 Claims, 4 Drawing Figures 1 FLUID CONTROL APPARATUS CROSS REFERENCE TORELATED APPLICATION This application is a continuation-in-part of myprior copending application filed on Nov. 3, l97l bearing Ser. No.195,250, now abandoned, for Adjustable Drilling Fluid Choke withProgressive Reduced Pressure zones.

DISCUSSION OF PRIOR ART The prior art with which applicant is familiarcomprises the US. Pats. to H. B. Lee, No. 1,645,601 and H. D. Baumann,No. 3,485,474.

The present invention differs over the above references in that acylindrical double acting ram surrounds a plurality of orifice platesand chambers in a housing. A conical member is mounted on one end of thecylindrical ram and movement of the ram positions the conical member tocontrol flow through the housing.

An object of the present invention is to provide an apparatus forcontrolling the flow from a variable pressure source in response to thepressure in the source.

Yet a further object of the present invention is to provide housingmeans with an inlet and outlet for receiving flow from a source and fordischarging flow from the housing. Flow constrictor means comprising aplurality of spaced orifice plates mounted in the housing definechambers therebetween for receiving flow from the source into thehousing, double acting ram means is movably and sealably mounted in saidhousing and supports a single conical member thereon for movement intoand out of the orifice plates and chambers for controlling the flow areaand flow restriction of the flow from the source as it passes throughthe housing.

Yet a further object of the present invention is to provide housingmeans with an inlet and outlet for receiving flow from a source and fordischarging flow from the housing, flow constrictor means comprising aplurality of spaced orifice plates mounted in the housing definechambers therebetween for receiving flow from the source into thehousing, double acting ram means is movably and sealably mounted in saidhousing and supports a single conical member thereon for movement intoand out of the orifice plates and chambers for controlling the flow areaand flow restriction of the flow from the source as it passes throughthe housing, said flow constrictor means including seat means wherebythe conical member may be seated to close off flow through the housingto function as a blowout preventor.

Other objects and advantages of the present invention will becomeapparent from a description of the following description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective viewillustrating a form of the present invention and a form of the operatingmeans for actuation of the device;

FIG. 2 is a sectional view illustrating in greater detail the structuraldetails of the present invention;

FIG. 3 is a sectional view on the line 3-3 of FIG. 2; and

FIG. 4 is a schematic illustration diagramatically illustrating variousgeometrical parameters for determining the flow area of any orifice orchamber within the housing of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention will bedescribed in detail in connection with its use in the drilling of wellssuch as oil and gas wells by rotary drilling tools well known in theart; however, such description is for purposes of illustration only, asthe present invention may be employed to dynamic fluid flow control inother systems.

In the course of drilling oil and gas wells by the rotary method it isdesirable to prevent uncontrolled, premature production of formationfluid.

To aid in overcoming such undesired occurrence a drilling fluid iscirculated downwardly through the drill string and discharged out thedrill bit at the lower end of the drill string and then circulated backup around the drill string in the well bore annulus to the earthssurface. Such circulation is continued throughout the drillingoperations and accomplishes a number of desirable functions within thewell bore one of which is to provide a fluid of sufficient density tocreate a hydrostatic head in excess of various formation pressures thatmay be encountered during the drilling operation.

In some situations formations are encountered while drilling that haveformation pressures in excess of the circulating fluid hydrostatic head.It is desirable to correct such situation to prevent what is normallytermed a blowout this is, the circulating fluid and excess formationpressure may be discharged from the well which, under some circumstancescan cause complete loss of the well being drilled.

The present invention provides a method and arrangement for maintainingthe well bore pressure in the annulus within a predetermined range, orto maintain a desired back pressure on the well bore annulus so that thestatic head of the circulating drilling fluid will always be greaterthan that of any formation which may be encountered to inhibit blowouts.

This invention may also function as a blowout preventor to completelyclose in the well bore annulus and close off discharge of thecirculating fluid to aid in preventing uncontrolled or undesirable flowdischarge rates of the circulating fluid from the well bore annulus.

Some drilling fluids employed have abrasive characteristics which maycause substantial erosion on some types of choke devices employed, andthe present invention is constructed and arranged to accomplish itsfunction with a minimum wear on the components from the circulation ofabrasive drilling fluids.

Referring first of all to FIG. 1, the present invention is referred togenerally by the numeral 15 and includes housing means 16 in which theflow constrictor means is referred to generally at 20 in FIG. 2. Acontrol arrangement referred to generally at 30 is responsive to theflow into the housing at inlet 31 for operating the flow constrictormeans 20 in response to the pressure from the source as measured atinlet 31 to housing 16. The inlet 31 may be provided with suitablethreads or the like for connecting with the conduit 41 whichcommunicates pressure from the source to the inlet 31 of the housing 16.The housing 16 also includes outlet 33 for discharge of the fluid flowtherefrom.

Suitable means such as a pressure transducer referred to generally at isprovided in the conduit 41 which connects with the inlet 31 of housing16 for conducting variable fluid pressure from a source which forpurposes of illustration is the discharge from the well bore annulus.The transducer 40 functions as will be described in greater detail toactuate valve means generally referred to at 45 so that power may besupplied to a suitable motor means (not shown) for actuation of thehydraulic pump for supplying hydraulic fluid to either the hose 51 orthe hose 52 for purposes as will be described. When hydraulic pressureis supplied by the pump means 50 through the hydraulic conduit 51 forexample, hydraulic fluid from the conduit 52 is discharged back into ahydraulic sump referred to by the letter S in a manner as will bedescribed.

The housing 16 is preferably of a cylindrical configuration and maycomprise any suitable number of cylindrical components and 61 which maybe threadedly connected together as illustrated at 62. Suitable sealmeans 63 are provided between the threads 62 to provide a seal betweenthe portions 60 and 61 of the housing 16.

The flow constrictor means 20 is better shown in FIG. 2 and includes aplurality of orifice plates 80, 81 and 82 which are maintained in spacedrelation by the spacers 83, 84 and 85. The orifice plates 80, 81 and 82as well as the spacers 83, 84 and 85 are carried within the cylindricalmember mounted in housing 16 in any suitable fashion. The orifice plate82 may be threadedly secured in the end of the cylindrical member 90 asshown in FIG. 2 of the drawings. The orifice plates 80, 81 and 82 eachhave central axially aligned openings 80a, 81a, and 82a.

The cylindrical member 90 is of substantially smaller diameter than thecylindrical members 60 and 61 as shown in FIG. 2 and is coaxialtherewith and with inlet 31 in housing 16. The annular space betweencylindrical member 90 and housing portion 61 defines a cylindricalchamber 100 for accommodating movement of hollow cylindrical ram as willbe described. The cylindrical ram 95 surrounds cylindrical portion 90and is provided with a flange 96 adjacent one end having an annular seal97 thereon for slidably and sealably engaging the inner periphery 98 ofthe housing 16 when the cylindrical ram 95 moves in chamber 100 as willbe described. The hollow cylindrical ram 95 moves on cylindrical member90 and the seal means 103, 104 and 116 inhibit leakage of fluid fromcylindrical chamber portion 100, as well as preventing commingling ofoperating fluid for the constrictor means 20 and the fluid from thesource passing through housing 16 and constrictor means 20.

The cylindrical portion or chamber 100 of the housing 16 is defined byone end wall 101 of the housing 16 and the annular member 102 which isthreadedly engaged adjacent the end of the cylindrical portion 61 ofhousing 16 as shown in FIG. 2. Suitable seal means 103 and 104 areprovided on each annular edge of the annular member 102 so as to sealrespectively with the outer periphery 105 of ram 95 and the innerperiphery 98 of cylindrical portion 61 of housing 16, as previouslynoted.

Fittings 51a and 52a are provided in openings and 1 l 1 of cylindricalsection 61 for engaging with hydraulic hoses 51 and 52 so that hydraulicfluid may be applied on either side of the ram 95, thus making it doubleacting in function. The flange 96 with seal 97 thereon as well asannular member 102 provide a closed chamber 100 within which theoperating hydraulic fluid to operate ram 95 may be discharged, butprevents commingling of such hydraulic fluid with the fluid passingthrough the housing 16 which is being controlled, as noted previously.

The end 113 of ram 95 is provided with discharge outlets 114 thatcommunicate with the chamber 115 that surrounds an extension on the endof the conical member which extension mounts the conical member 120 onthe end of ram 95 in any suitable manner as shown in FIG. 2 of thedrawings.

The conical member 120 faces upstream within the orifice plates 80, 81and 82 and chambers 125, 126 and 127 formed therebetween toward theinlet 31 of housing 16. The ram 95 is provided with an annular shoulder95a spaced from flange 96, which shoulder engages annular member 102 andlimits movement of ram 95 in chamber 100. When the ram is in theposition as illustrated in FIG. 2 it is seated on the orifice plate 82and closes off flow through the housing. It will be noted that theorifice plate 82 is provided with a seat 82a for receiving the seat 120aformed 0 the extension at the end of conical member 120, and it will befurther noted that the orifice plate 82 is the furthest orifice platefrom the inlet 31 of the housing 16. i

The arrangement of the orifice plates 80, 81 and 82 with the spacers 83,84 and 85 therebetween provide turbulence flow chambers 125, 126 and127. It will be noted that each turbulence chamber is tapered as shown.Of course, it can be appreciated that any number of orifice plates andany number of spacers may be provided to form or define any number ofchambers as may be desired. In such event, the length of the conicalmember 120 will be adjusted accordingly so that when it is in fullyclosed position as shown in FIG. 2 of the drawings the apex 130 thereofwill be at the left end of chamber 125 adjacent inlet 31 as shown inFIGS. 2 and 4 of the drawings.

In the operation of the present invention, the transducer 40 detects thepressure of the fluid from the source conducted to the inlet 31 ofhousing 16 and to be controlled therein. Depending upon the type oftransducer, a signal will be transmitted, either electrically orhydraulically, or pneumatically through conduit 40 to actuate valvemeans represented generally at 45. The valve means 45 may be a springloaded type so that it can be preset to maintain any desired flowcontrol conditions in housing 16. For example, valve means 45 may be setso that should the pressure into the inlet 31 of housing 16 exceed apredetermined amount, such valve means will function to supply powerfrom any suitable source such as from an air source on the drilling rigthrough the conduit to operate an air motor which in turn operates thepump 50. The valve means 45 will further function so as to communicateconduit 51 with the discharge side of the pump means 50 whereby fluidmay be discharged into the chamber 100 to move the ram 95 towards theleft as illustrated in FIG. 2 of the drawings to cause the conicalmember to seat and close off flow through the device. In such event,undesired or unwanted discharge of fluid from the well bore annulus whenit exceeds a predetermined pressure may be accomplished.

Similarly, the valve means 45 may be set so that, depending upon thepressure from the variable source as measured at the inlet by thetransducer 40, such valve means function to move the ram 95 to the rightor to the left by supplying fluid through either the hydraulic hose 51or hydraulic hose 52. It can be appreciated that when the hydraulic ramis moved in one direction by hydraulic fluid acting on one side thereof,the other hose acts as a discharge to discharge the hydraulic fluid fromthe other side of the ram back to the pump S with which the pump 50communicates by means of its intake. The valve means 45 functions toconnect the discharge of pump means 50 with either hose 51 or 52,depending upon the signal received from transducer 40.

The positioning of the conical member 120 relative to the orifice plates80, 81, and 82 and chambers 125, 126 and 127 will thus depend upon thepressure of the source being controlled. In some situations the conicalmember will be moved only partially in one or more of the orificeplates, and under some circumstances, it can be appreciated that the ram95 will be moved to the right (as viewed in FIG. 2) when the pressuremeasured by the transducer 40 at the inlet 31 of housing 16 indicatesthat such should occur so as to provide less restriction to fluid flowthrough the choke device.

Thus, the flow constriction means functions as a throttling valvearrangement to control the discharge of the fluid being controlled bythe present invention from the housing 16 and through discharge conduit150. It will be noted that the closure member which is in the form ofthe conical member 120a is configured so as to provide a minimum oferosion thereto while accomplishing its function.

It will be noted that the spacers 83, 84 and 85 form a conicallydiverging passage from the inlet 31 to the valve seat 82a so as toreduce pressure of the fluid by volumetric expansion. The crosssectional flow area through a portion of the choke passage is determinedby the dimensions of the cone member 120 and the actual position of suchcone relative to any one or more of the orifice plates in the flowconstrictor means 20.

The apex 130 of conical member 120 is at beginning of the first chamber125 when the member 120 is seated as shown in FIG. 2.

As drilling fluid enters the choke device of the present invention, itundergoes the desired pressure and flow control as the valve means 45 isoperated by the transducer 40, and depending upon the conditions desiredwithin the control device. Of course, such conditions are determined andthe valve means then set accordingly so as to react properly to thetransducer 40 to position the cone member 120 relative to the chambers125, 126 and 127 to accomplish the desired pressure and flow restrictionupon the fluid pressure from the source. In some situations, it may bedesirable to manually control the present invention and in such eventmeans 160 may be employed to operate valve means 45 so that the motormeans and pump means 50 is actuated as desired to control the positionof ram 95.

The housing 16 may be supported on any suitable frame as indicated at16a in FIG. 1.

FIG. 4 illustrates the geometric parameters associated with the specificembodiment herein described. By selection of components of differentdimensions, including the cone member 120, orifice plates 81, 82 and 83as well as spacers 83, 84 and 85, different design requirements may beobtained.

Of course, in addition to the selection of the aforementionedcomponents, dimensional flow relationship will vary in accordance withthe position of the cone member relative to the various orifice platesand chambers. The flow area relationships are indicated in the followingequations:

In the above equations the following definitions app y= Ac is the flowarea of any chamber under consideration, or being calculated;

R0 is the radius of the housing inlet;

L0 is the distance from the beginning of the first chamber adjacent theinlet of said housing to the midpoint of the chamber whose flow arearelationship is being calculated;

(1) is the angle of the taper on the conical member;

0 is the angle of the taper of the turbulence chambers;

D is the distance from the beginning of the first chamber at the inletof the housing to the apex of the conical member;

(At) is the flow area of the orifice opening whose flow area is beingcalculated.

Ln is the distance from the beginning of the first chamber at the inletof housing 16 to the midpoint of the orifice plate whose flow area isbeing calculated;

Tn is the thickness of the orifice plate member whose flow area is beingcalculated.

Theoretical flow conditions on the other hand will be in accordance withthe following equations:

Wherein V is flow velocity, 0.95 is the coefficient of orifice platetaken as 0.95, P is static pressure, Q is flow rate, p is fluid density,Ht is head loss at the orifice opening, H0 is head loss at anyturbulence chamber and T1 and I2 is the thickness of orifice platesdesignated in FIG. 4 as 1 & 2 inscribed in a circle.

The foregoing construction enables dimensional selection of componentsby computer programming and in order to meet any design flow conditionsdesired. The orifice plates and chambers assist in functioning to causestepwise pressure and velocity reduction as desired, and createturbulence in chambers to dissipate energy, thereby reducing wear anderosion thereby minimizing stress failure on the components of thestructure. The conical member further reduces erosion by itsconfiguration and absorbing the impact of the abrasive particles in thedrilling fluid and also provides a method of controlling fluid flow byvarying the flow area along the choke passage through the flowconstrictor means 20 within the housing 16.

When the fluid is discharged from openings 114, it passes into thechamber formed by cylindrical portion 60 of housing 16 and is thendischarged through outlet 33 of housing 16.

Thus, the constrictor means 20, by positioning conical member 120relative to one or more of the orifice plates and chambers aids inreducing pressure and velocity of the pressure from the variable source.

As a result of the foregoing arrangement the fluid from the source, suchas drilling fluid entering the choke device of the present inventionundergoes a graduated, controlled reduction of both pressure andvelocity between the inlet 31 and outlet chamber formed in cylindricalportion 60. The arrangement of the present invention is such that thereare no major areas or wear surfaces that can receive severe stressreversals or destructive direct impact of high velocity abrasiveparticles.

A pressure transducer may be applied to the inlet of the mud supply atthe drilling string and a conduit such as the conduit 40 then connectedfrom such transducer to the valve means 45 so that the present inventionis controlled by the inlet pressure to the drill string rather than theoutlet pressure.

The foregoing disclosure and description of the invention areillustrative and explanatory thereof, and various changes in the size,shape, and materials as well as in the details of the illustratedconstruction may be made without departing from the spirit of theinvention.

I claim:

1. An apparatus for controlling fluid flow from a source comprising:

a. housing means having an inlet for receiving flow from the source andan outlet for discharging flow from the housing;

b. flow constrictor means mounted within said housing and including;

1. a plurality of spaced orifice plates mounted in said housing andproviding chambers therebetween for receiving flow from the source intosaid housing;

2. double acting cylindrical ram means surrounding said orifice platesand chambers and movably and sealably mounted in said housing;

3. a single conical member mounted on said ram means at one end thereofand movable into and out of said spaced orifice plates and chambers;

4. said orifice plate which is spaced furthest from the apex of saidconical member forming a seat for receiving said conical member to closeoff flow through said housing; and

c. means responsive to the fluid pressure from the source for movingsaid flow constrictor means to position said conical member relative tosaid orifice plates and chambers to thereby control flow from the sourcethrough said housing.

2. The invention of claim 1 wherein said responsive means for operatingsaid flow constrictor means comprises:

a. transducer means for determining the pressure from the source;

b. pump means for pumping hydraulic fluid to act on said ram means;

c. motor means for operating said pump means;

d. valve means operable by said transducer means for actuating saidmotor means; and

e. valve means operable by said transducer means for controlling theflow of the hydraulic fluid to either side of said ram means to positionsaid conical member relative to said orifice plates and chambers tocontrol the flow from the source through said housing in response to thesource pressure.

3. The invention of claim 1 wherein the flow area relationship withinsaid housing is defined as follows:

In the above equations the following definitions ap ply:

Ac is the flow area of any chamber under consideration, or beingcalculated;

R0 is the radius of the housing inlet;

Lc is the distance from the beginning of the first chamber adjacent theinlet of said housing to the midpoint of the chamber whose flow arearelationship is being calculated;

d) is the angle of the taper on the conical member;

0 is the angle of the taper of the turbulence chambers;

D is the distance from the beginning of the first chamber at the inletof the housing to the apex of the conical member;

(At) is the flow area of the orifice opening whose flow area is beingcalculated.

Ln is the distance from the beginning of the first chamber at the inletof housing 16 to the midpoint of the orifice plate whose flow area isbeing calculated;

Tn is the thickness of the orifice plate member whose flow area is beingcalculated.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION 3,791,621 DatedFebruary 12, 1974- Patent No.

lnventofls) Asadollah Hayatdavoudi It is certified that error appears inthe above-identified patent and that said Letters Patent are herebycorrected as shown below:

001.7, line +5, Claim '1 "flow constrictor" should be ram Col. 5, line30 "120a" should be l20- Col. 6, line 44, "12" should be -T2'- Signed'and sealed this 17th day of September 1974.

(SEAL) Attest:

McCOY M. GIBSON JR. C. MARSHALL DANN Commissioner of Patents AttestingOfficer USCQMM'DC 6O376-Pb9 U45. GOVERNMENT PRINTING OFFICE: 19GB 0-36-334.

FORM PO-1050 (10-69)

1. An apparatus for controlling fluid flow from a source comprising: a.housing means having an inlet for receiving flow from the source and anoutlet for discharging flow from the housing; b. flow constrictor meansmounted within said housing and including;
 1. a plurality of spacedorifice plates mounted in said housing and providing chamberstherebetween for receiving flow from the source into said housing; 2.double acting cylindrical ram means surrounding said orifice plates andchambers and movably and sealably mounted in said housing;
 3. a singleconical member mounted on said ram means at one end thereof and movableinto and out of said spaced orifice plates and chambers;
 4. said orificeplate which is spaced furthest from the apex of said conical memberforming a seat for receiving said conical member to close off flowthrough said housing; and c. means reSponsive to the fluid pressure fromthe source for moving said flow constrictor means to position saidconical member relative to said orifice plates and chambers to therebycontrol flow from the source through said housing.
 2. double actingcylindrical ram means surrounding said orifice plates and chambers andmovably and sealably mounted in said housing;
 2. The invention of claim1 wherein said responsive means for operating said flow constrictormeans comprises: a. transducer means for determining the pressure fromthe source; b. pump means for pumping hydraulic fluid to act on said rammeans; c. motor means for operating said pump means; d. valve meansoperable by said transducer means for actuating said motor means; and e.valve means operable by said transducer means for controlling the flowof the hydraulic fluid to either side of said ram means to position saidconical member relative to said orifice plates and chambers to controlthe flow from the source through said housing in response to the sourcepressure.
 3. a single conical member mounted on said ram means at oneend thereof and movable into and out of said spaced orifice plates andchambers;
 3. The invention of claim 1 wherein the flow area relationshipwithin said housing is defined as follows: Ac pi (Ro+Lctan theta )2- pi((Lc-D) tan phi )2 At pi (Ro+Lntan theta -Tnsec theta )2- pi ((Ln-D) tanphi )2 In the above equations the following definitions apply: Ac is theflow area of any chamber under consideration, or being calculated; Ro isthe radius of the housing inlet; Lc is the distance from the beginningof the first chamber adjacent the inlet of said housing to the midpointof the chamber whose flow area relationship is being calculated; phi isthe angle of the taper on the conical member; theta is the angle of thetaper of the turbulence chambers; D is the distance from the beginningof the first chamber at the inlet of the housing to the apex of theconical member; (At) is the flow area of the orifice opening whose flowarea is being calculated. Ln is the distance from the beginning of thefirst chamber at the inlet of housing 16 to the midpoint of the orificeplate whose flow area is being calculated; Tn is the thickness of theorifice plate member whose flow area is being calculated.
 4. saidorifice plate which is spaced furthest from the apex of said conicalmember forming a seat for receiving said conical member to close offflow through said housing; and c. means reSponsive to the fluid pressurefrom the source for moving said flow constrictor means to position saidconical member relative to said orifice plates and chambers to therebycontrol flow from the source through said housing.